Abstract: Objectives　To investigate the relationship between congenital nephrotic syndrome (CNS) and neonatal polycythemia, and clinical diagnosis and treatment. Methods　The clinical manifestations, diagnosis, and treatment of a case of CNS with neonatal polycythemia were retrospective analyzed, and the related literature were reviewed. Results　A male infant had abdominal distention after his birth, followed by feeding intolerance and poor response. On the third day of birth, he was diagnosed of neonatal polycythemia according to the levels of hemoglobin (249 g/L) and hematocrit (0.714 L/L). And after a partial exchange transfusion, the symptoms were improved. On the sixth day of birth, the infant had edema, urinary protein +++, serum albumin at 12.7 g/L and blood cholesterol at 8.84 mmol/L, and was clinical diagnosed of CNS. Oral hormone therapy was ineffective and he died 32 days after birth. Conclusions　CNS combined with neonatal erythrocytosis is rare in clinic. The coexisting of the two is more likely to induce thromboembolism and organ dysfunction, and the clinical prognosis is poor.